19997473 has 2 divisors, whose sum is σ = 19997474. Its totient is φ = 19997472.

The previous prime is 19997459. The next prime is 19997477. The reversal of 19997473 is 37479991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19430464 + 567009 = 4408^2 + 753^2 .

It is an emirp because it is prime and its reverse (37479991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19997473 - 2⁵ = 19997441 is a prime.

It is not a weakly prime, because it can be changed into another prime (19997477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9998736 + 9998737.

It is an arithmetic number, because the mean of its divisors is an integer number (9998737).

Almost surely, 2^19997473 is an apocalyptic number.

It is an amenable number.

19997473 is a deficient number, since it is larger than the sum of its proper divisors (1).

19997473 is an equidigital number, since it uses as much as digits as its factorization.

19997473 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 49.

The square root of 19997473 is about 4471.8534188857. The cubic root of 19997473 is about 271.4303289558.

The spelling of 19997473 in words is "nineteen million, nine hundred ninety-seven thousand, four hundred seventy-three".